1. Field of the Invention
The present invention relates to an elevator and a guide device for an elevator having an actuator to reduce the vibration of a cage.
2. Description of the Related Art
In an elevator, an elevator car is guided by guide rails in such a manner that guide elements of guide devices provided in the elevator car including a cage come into contact with the guide rails vertically arranged on side walls of a hoistway. However, errors occur in the installation of the guide rails, and further deflection is caused in the guide rail by a load given to the cage, and furthermore a small level difference and winding are caused in the guide rail by the change with age. Therefore, when the cage of the elevator car is run, it is affected by an external disturbance caused by the level difference and winding of the guide rail. Accordingly, the cage is vibrated in the up and down direction (elevating direction) and the side to side direction (direction perpendicular to the elevating direction). As a result, passengers feel uncomfortable.
Conventionally, in order to reduce the longitudinal and the lateral vibration, an elastically supporting member or a vibration isolating member for reducing an input of displacement given by the guide rail is arranged between the cage and the car frame or between the car frame and the guide element. In order to provide a great effect of isolation of vibration, it is necessary to reduce the rigidity of the elastically supporting member and the vibration isolating member. On the other hand, in order to prevent the occurrence of interference of the cage with other components when an imbalance load is given to the cage, it is necessary to somewhat increase the rigidity. For the above reasons, it is difficult to design an elevator by which a sufficiently high vibration isolating effect can be provided and at the same time no problems are caused even if an imbalanced load is given to the cage.
Accordingly, when the elastically supporting member or the vibration isolating member, by which an input of displacement given to the cage is only passively reduced, is provided, it is impossible to solve the problems caused when the elevating speed of an elevator is increased.
Therefore, attention is given to an active vibration isolating method, in which a force to suppress vibration is given from the outside, instead of the passive vibration isolating method. Especially, there is proposed an active vibration isolating method in which an electric current is made to flow in a coil so as to generate a magnetic field at the center (axial center) of the coil, and vibration is reduced by a magnetic force when a reaction bar made of magnetic body is arranged at a position opposed to the magnetic field.
FIG. 13 is a cross-sectional view showing an example of an elevator device to which the above active vibration isolating method is applied, which is described in Japanese Unexamined Patent Publication No. 6-92573.
As shown in FIG. 13, there is provided a car frame 101 for supporting a cage, and a support base 102 is fixed to the car frame 101. A support arm 103 extending in the vertical direction (elevating direction) is pivotally attached to this support base 102. In this support arm 103, there is provided a roller 105 that rotates coming into contact with a rail 104 vertically arranged on a side wall of a hoistway. An arm 106 (reaction bar) extending in the horizontal direction is pivotally attached to the support base 102, and this arm 106 is connected with the support arm 103. Due to the above structure, when the arm 106 is driven, the support arm 103 is driven.
In the car frame 101 under the arm 106, there is provided an electromagnetic induction member 107 round which a coil is wound. This electromagnetic induction member 107 round which a coil is wound composes a stationary section of an actuator. On the other hand, the arm 106 located above this electromagnetic induction member 107 is made of magnetic substance. This arm 106 (reaction bar) composes an movable section of the actuator.
In order to suppress the occurrence of vibration of the cage, an electric current is made to flow in the coil so as to generate a magnetic field in the electromagnetic induction member 107 in the vertical direction. The arm 106 is attracted by a magnetic force generated by this magnetic field in the vertical direction. As a result, the support arm 103 is driven, so that an intensity of the exciting force transmitted to the car frame 101 can be reduced. In this connection, at this time, a magnetic field in the vertical direction is generated by the electromagnetic induction member 107, that is, a magnetic field is generated on the moving plane of the arm 106.
Due to the above structure of the conventional elevator, a positional relation between the movable section and the stationary section of the actuator is changed by a static displacement by which the cage is tilted by an imbalance load and also by a dynamic displacement by which a position of the movable section of the actuator is changed by the drive of the actuator. Therefore, compared with a case in which the static and the dynamic displacement are not caused, a magnetic force given to the movable and the stationary section of the actuator is changed.
Accordingly, the magnetic force generated in the case of the static displacement and the magnetic force generated in the case of the dynamic displacement are different from each other. However, when the actuator is controlled, a control method is adopted which is suitable for a case in which no displacements are caused. Therefore, it is impossible to conduct an appropriate control. As a result, a drive force of the actuator can not act properly. It can be considered to adopt a method in which it is judged whether the static displacement and the dynamic displacement exist or not. However, when the above method is adopted, it is necessary to conduct a complicated and difficult control.
The present invention has been accomplished to solve the above problems. It is an object of the present invention to provide an elevator and a guide device of the elevator provided with an actuator characterized in that: a drive force to drive the actuator acts properly even when the static and the dynamic displacement are caused so that a sufficiently high vibration isolating effect can be provided.
The present invention provides an elevator comprising: an elevator car including a cage which runs in a hoistway along a pair of rails vertically arranged on side walls in the hoistway; and a plurality of guide devices for guiding the elevator car along with the pair of rails, attached onto the rail sides of the elevator car, each guide device including: a guide lever pivotally attached to a support member fixed to the elevator car or pivotally attached to the elevator car, so that the guide lever can be driven on a moving plane; a guide element for guiding the elevator car along the rail, being attached to the guide lever and coming into contact with the rail vertically arranged on the side wall of the hoistway; and an actuator device having a stationary actuator part fixed to the support member or the elevating member and also having a moving actuator part fixed to the guide lever and driven on the moving plane, wherein one of the moving actuator part and the stationary actuator part is a magnet for generating a magnetic field crossing a drive direction of the moving actuator part, the other of the moving actuator part and the stationary actuator part is a coil arranged so that the coil can be influenced by the magnetic field, and a Lorentz""s force for driving the moving actuator part in the drive direction of the moving actuator part is generated by supplying an electric current in the coil when the elevator car is vibrating, so that the guide lever is driven by the Lorentz""s force so as to suppress the vibration of the elevator car.
The magnet is arranged so that it can generate a magnetic field in a direction crossing the moving plane of the guide lever.
The magnet is arranged so that it can generate a magnetic field in a direction perpendicular to the moving plane of the guide lever, and the central axis of the coil is included on the moving plane of the guide lever.
The guide lever is driven in a predetermined region on the moving plane, and an area in which the coil and the magnetic field cross each other becomes constant with respect to the drive of the guide lever in the predetermined region.
The magnet is arranged so that it can cover a region in which the coil is moved when the guide lever is driven.
The magnet is composed of a pair of magnets arranged being opposed to each other with respect to the moving plane of the moving actuator part, a yoke member located at a predetermined distance from each magnet is arranged between the pair of magnets, and the coil is arranged in such a manner that the coil surrounds the yoke member so that the yoke member and the coil can not be contacted with each other when the moving actuator part is driven.
A guide device for an elevator of the present invention comprises: a guide lever attached to a support member fixed to an elevator car including a cage which runs in a hoistway along a pair of rails vertically arranged on side walls in the hoistway, the guide lever being driven on a moving plane; a guide element for guiding the elevator car along the rail, being attached to the guide lever and coming into contact with the rail vertically arranged on the side wall of the hoistway; and an actuator device having a stationary actuator part fixed to the support member and also having a moving actuator part fixed to the guide lever and driven on the moving plane, wherein one of the moving actuator part and the stationary actuator part is a magnet for generating a magnetic field crossing a drive direction of the moving actuator part, the other of the moving actuator part and the stationary actuator part is a coil arranged so that the coil can be influenced by the magnetic field, and a Lorentz""s force for driving the moving actuator part in the drive direction of the moving actuator part is generated by supplying an electric current in the coil when the elevator car is vibrating, so that the guide lever is driven by the Lorentz""s force so as to suppress the vibration of the elevator car.
The magnet is arranged so that it can generate a magnetic field in a direction crossing the moving plane of the guide lever.
The guide lever is driven in a predetermined region on the moving plane, and an area in which the coil and the magnetic field cross each other becomes constant with respect to the drive of the guide lever in the predetermined region.